Difficult to drive through car parks, car has a tendency to either go in a straight line or go sideways, can't really go on the power around corners, you will KILL tyres, be lucky to get 5000k's out of a pair on the rear...
Have you ever heard a car with a CIG locker go through a car park? When they are going slowly around a corner, or turning, you will hear a steady 'scrub, scrub, scrub, scrub' sound...
Weld the diff and work it out mate, diffs are worth sweet f@$k all, i've never paid for a single spinner diff.